Final answer:
The 19th Amendment dramatically changed the U.S. government by granting women the right to vote.
Step-by-step explanation:
The amendment that dramatically changed the U.S. government is the 19th Amendment. Ratified in 1920, this amendment granted women the right to vote. It significantly expanded democratic participation by allowing for the inclusion of women in the electoral process, thereby reshaping the political landscape of the country.
Learn more about 19th Amendment and its impact on U.S. government